Method of making retractile articles



Patented June 1, 1943 METHOD OF MAKING RETRACTILE ARTICLES Ren Picard and Ren Fays, Paris, France; vested in the Alien Property Custodian No Drawing. Application August 15, 1939, Serial No. 290,309. In France September 23, 1938 6 Claims.

This invention relates to retractile articles, and more particularly to retractile articles having a'high degree of plasticity.

Retractile articles, such as caps, bands, etc., formed of gelatin, regenerated cellulose, cellulose derivatives, etc. and having the property of shrinking upon conversion from a wet or gel state to the dry state, and firmly adhering to the article on which they have been applied, have been known for many years. Such articles, and

, particularly caps and bands, have been used to or slightlyswollen state, was applied to the desired article as, for example, over the closure or on theneck of the bottle and converted to the dry state. Upon drying, the cap or band shrank or contracted, with the result that it tightly gripped the article to which it had been applied and also conformed to the shape thereof. Preferably, the contraction and shrinking was irreversible in order to prevent the closure from being broken without deterioration of or damage to the cap.

According to the prior art procedures, due to the fact that the cap was oversize and was freely disposed in its desired position, a certain degree of drying was necessary for the cap to begin to grip the neck so as to cause it to adhere sufiiciently and permit manipulation of the capped article. This required preliminary drying before manipulating the capped article was a disadvantage for certain uses where a large number of articles had to be handled rapidly. Rapid driers for caps have been utilized, but such driers were expensive and offered only partial solution of the difficulties. Consequently, the difficulties and disadvantages just mentioned greatly restricted the market for said caps.

In order to overcome the above-mentioned inconvenience, it has also been proposed to make use of the elasticity possessed by the moist caps. Specifically, it has been proposed to stretch the caps by means of stretching devices and, after the caps have been positioned in place, to withdraw the stretching devices. However, because of the lack of plasticity of the caps, a great many of the caps upon being stretched were torn or otherwise damaged, with the result that this procedure was inapplicable in practice.

The object of the instant invention is to provide retractile articles, such as caps, bands, etc., having a sufficient degree ofplasticity and elascharacteristics:

in position on the article and immediately adhere sufliciently tightly and conform to the article to be capped to permit immediate handling" of the article to which. the retractile article is applied. v

Another object of this invention consists in a method of manufacturing retractile articles, such as caps, bands, etc., whichimparts to them a degree of plasticity and elasticity, permitting the stretching thereof whereby said articles may be mounted in place on the article and thereafter immediately adhere sumciently to the article to be capped to permit immediate handling of the article to which the retractile article is applied.

Other objects will appear from the following description and appended claims. For purposes of convenience and brevity, the invention will be described specifically in connection with caps, though it is to be understood that the invention is not restricted thereto and is equally applicable to all types of retractile articles.

In accordance with the principles of the instant invention, a cap formed of a cellulose derivative insoluble in water and while in the gel state is treated with a substance which imparts a high degree of plasticity to the cap in the gel state. The substance with which the cap in the gel state is impregnated must have the following 1. It must be miscible with water in large proportions 2. It must be a solvent or swelling agent of the cellulose derivative constituting the cap; and

3. It must be sufliciently volatile to be largely eliminated during drying.

Derivatives of polyhydric alcohols, and particularly derivatives of glycols and glycerols, may be mentioned as substances which will impart the desired properties of plasticity, 'elasticity, extensibility, etc. to caps formed of cellulose esters.

.As derivatives of glycols which have given satisfactory results may be mentioned those having the following general formula:

wherein:

X is a radical of glycol; R is a radical of a lower fatty acid or a halogen;

' R. is a hydroxyl group, a radical of a lower fatty ticity so that they can be stretched and mounted acid, oran alkoxylradical containing 1 to 2 C atoms.

As illustrative specific examples of derivatives of glycols which have given satisfactory results may be mentioned monoformate of glycol, monoacetate of glycol, diacetate of glycol, and monochlorhydrin of glycol. As specific illustrative examples of derivatives of glycerols which have given satisfactory results may be mentioned glycerol monoacetate, glycerol diacetate, glycerol triacetate, and glycerol monochlorhydrin.

It is to b understood that one or a plurality of the glycol derivatives or one or a plurality of the glycerol derivatives, or combinations of both the derivatives of glycol and the derivatives of glycerol, may be used.

It is further to be noted that the plasticizing solutions are neutral and thus do not impart any undesirable properties to products treated therewith.

By means of a judicious choice of proportions, a choice that can be made by any one skilled in the art, caps are obtained which possess elongations of rupture in all directions of from 30%-100% in the moist state, and can be mounted, by virture of said property, on bottle necks of many different dimensions by merely stretching them by means of appropriate apparatus. Immediately after having been placed in position, the caps begin to take on the shape of the necks or articles.

Caps prepared according to this invention do not immediately contract fully. Full contraction is produced and obtained only upon complete drying. However, on stretching and placing the caps in position, they grip the article sufilciently to allow the latter to be handled without any trouble. for example for the purpose of wrapping.

During the drying process, both the water and the incorporated substance are eliminated, the cap loses its extensibility and cannot be removed from the neck of the bottle without being damaged, which prevents its being tampered with. a

Another advantage offered by the present invention is the possibility of applying caps of given dimensions to closures of bottles of various dimensions in much greater proportion than was possible with ordinary caps. duction'of the number of sizes that the manufacturer must have in stock-The result of this is a great simplification in manufacturing and the necessary material, a reduction in the cost price, and greater convenience for the user.

In order to more clearly explain the instant invention, there are hereafter set forth several specific illustrative examples.

Example I.-In a solution of cellulose acetate (triacetate), there is immersed an appropriate glass mold on which a layer of the solution ad- This permits a re-.

heres upon withdrawal of the mold from the solution. The adhering layer of solution is then coagulated by means of water or dilute acids. After complete coagulation, the articles are thoroughly washed and rinsed, cut to the desired length if desired, and removed from the molds. The articles removed from the mold, and while still in the gel state, are impregnated as by immersion in a solution consisting of 5 to 40 parts of monochlorhydrin of glycol and 1 to 10 parts of triacetin dissolved in parts of water. The impregnated caps are preferably then appropriately treated to remove the solution adhering to the surface thereof, after which they are wrapped while still moist in impermeable containers, for example boxes.

Example IL-Same as Example I, except that the following solution is used in place and stead of that set forth in Example I: a saturated aqueous solution of diacetate of glycol to which restricted thereto, since it is equally applicable to any water-insoluble cellulose derivative.

In our application Serial No. 290,310 filed on even date herewith, there is disclosed another method whereby retractile articles of the same type and nature as herein described are produced.

Since it is obvious that various changes and modifications may be made in the above description without departing from the nature or spirit thereof, this invention is not restricted thereto except as set forth in the appended claims.

We claim:

1. A method of forming retractile articles having sufficient plasticity and extensibility in the moist or gel state to permit stretching thereof, which comprises forming a solution of a waterinsoluble cellulose acetate into the desired shape and form, coagulating said solution while in said shape and form, impregnating the coagulated article while in the gel state with a plasticizer which is a swellingagent or solvent for the cellulose acetate, miscible with water in large proportions and sufliciently volatile to be largely eliminated during drying of said article, and maintaining the resulting retractile article in the moist or gel state until at least said article is positioned in place in the ultimate use thereof.

2. A method of forming retractile articles having sufficient plasticity and extensibility in the moist or gel state to permit stretching thereof, which comprises forming a solution of a waterinsoluble cellulose acetate into the desired shape and form, coagulating said solution while in said shape and form, impregnating the coagulated article while in the gel state with an aqueous solution containing a plasticizer for the cellulose acetate, said plasticizer being a swelling agent or solvent for the cellulose acetate, miscible with water in large proportions and sufficiently volatile to be largely eliminated during drying of said article, and maintaining the resulting retractile article in the moist or gel state until at least said article is positioned in place in the ultimate use thereof.

3. A method of forming retractile. articles having sufficient plasticity and extensibility in the moist or gel state to permit stretching thereof, which comprises forming a solution of a waterinsoluble cellulose acetate into the desired shape and form, coagulating said solution while in said shape and form, impregnating the coagulated article while in the gel state with a plasticizer consisting of a water-miscible derivative of a polyhydric alcohol which is suficiently volatile to be largely eliminated during drying, and maintainlating said solution while in said shape and form,

ing the resulting retractile article in the moist Y or gel state until at least said article is positioned in place in the ultimate use thereof.

4. A method of forming retractile articles having suflicient plasticity and extensibility in the moist or gel state to permitstretching thereof, which comprises forming a solution of a waterinsoluble cellulose acetate into the desired shape and form, coagulating said solution while in said shape and form, impregnating the coagulated article while in the gel state with an aqueous solution containing a plasticizer consisting of a water-miscible derivative of a polyhydric alcohol which is sufllciently volatile to be largely eliminated during drying, and maintaining the resulting retractile article in the moist or gel state until at least said article is positioned in place in the ultimate use thereof;

5. A method of forming retractile articles having sufllcient plasticity and extensibility in the moist or gel state to permit stretching thereof, which comprises forming a solution of cellulose triacetate into the desired shape and form, coaguimpregnating the coagulated article while in the gel state with a solution consisting of the following ingredients in the approximate proportions by weight:

Parts Monochlorhydrin of glycol 5 to Triacetin -1 to 10 Water and maintaining the resulting retractile article in the moist or gel state until at least said article is positioned in place in the ultimate use thereof.

6. A method of forming retractilearticles having sufiicient plasticity and extensibility in the moist or gel state to permit stretching thereof, which comprises forming a solution of cellulose triacetateinto the desired shape and form, coagulating said solution while in said shape and form, impregnating the coagulated article while in the gel state with a saturated aqueous solution of diacetate of glycol containing 1 to 6 parts of triacetin, the proportions being by weight, and maintaining the resulting retractile article in the moist or gel state until at least said article is positioned in place in the ultimate use thereof.

RENE PICARD. RENE FAYS. 

